Excluding electric drives, karts are generally driven by 2- or 4-stroke engines (much more rarely by Wankel engines). Regarding Racing karts, however, the 2-stroke engine is definitely predominant, even if 4-stroke motorized Racing classes with Briggs & Stratton and Tillotson engines are increasingly becoming popular. If in 4-stroke engines combustion is given by petrol while lubrication is oil based using a dedicated circuit, in 2-stroke engines combustion and lubrication take place thanks to a single element, the mixture, or a mix of oil-petrol in which the lubricant is suspended, in a uniform manner, inside the petrol. The important task of the mixture is to provide energy to the engine and at the same time properly lubricate all the components in friction, subject to high wear and exposed to high temperatures. 2-stroke engines are operated based on a pump crankcase that at first sucks the mixture from the carburetor and then, subsequently, pushes it into the combustion chamber making it travel the distance necessary for the total lubrication of the internal components. Therefore, the correct preparation of the mixture ensures correct operation, ideal performance, adequate reliability of the engine and... It avoids rather costly breakdowns.